冻干甲型肝炎减毒活疫苗H_2株的安全性和免疫原性研究

Studies on Safety and lmmunogenicity of Freeze-dried Live Attenuated Hepatitis A Vaccine (H_2 Strain)

为观察H2 株冻干甲型肝炎 (甲肝 )减毒活疫苗接种人体后的安全性和免疫原性 ,选择广西壮族自治区蒙山县一小学学生 (年龄 7～ 12岁 ) 16 4人和浙江省台州市椒江区一幼儿园儿童 (年龄 3～ 6岁 ) 114人为接种对象 ,免疫前筛选抗甲肝病毒IgG抗体 (抗 HAV IgG)阴性 ,血清丙氨酸氨基转移酶 (SGPT)正常 ,无肝炎病史、症状和体征者 ,分别接种 2个批号的H2 株冻干甲肝活疫苗。观察接种疫苗后 30min ,8、2 4、4 8、72h的局部及全身反应 ,以后隔天记录体温及其它有关临床反应。接种疫苗后 1、2个月采静脉血测定SGPT及抗 HAV IgG ,同时长期随访检测免疫后13、2 4个月血清抗 HAV IgG水平。检测用酶免疫测定 (EIA)竞争抑制法 ,用世界卫生组织 (WHO)提供的标准品(含 10 0mIU/ml)进行标定。结果显示 :在整个观察期间 ,所有观察者未见中、强反应及其它临床反应发生 ,SGPT检测结果无异常升高。H2 株冻干甲肝活疫苗具有良好的安全性。接种疫苗后 2个月抗体阳性率为 99 1%～10 0 0 % ,13～ 2 4个月阳性率仍高达 97 8%～ 98 9% ;免疫后 2个月抗体几何平均滴度 (GMT)达 16 0 7mIU/ml,在免疫后 2 4个月抗体GMT仍维持在 4 4 8 3mIU/ml。表明H2 株冻干甲肝活疫苗安全性良好 ,接种后有较高的抗体阳转率和GMT。

To assess the safety and immunogenicity of freeze-dried live attenuated hepatitis A (HA) vaccine (H_2 strain) inoculated to humans, we chose 164 primary school students of 7-12 years old from Mengshan County of Guangxi Autonomous Region and 114 kindergarten children of 3-6 years old from Jiaojiang District of Taizhou city of Zhejiang Province. They were all anti-HAV-IgG negative, SGPT normal, no hepatitis history and no hepato-symptoms. These two groups of subjects were inoculated separately with two different batches of freeze-dried live attenuated HA vaccine H_2 strain, and then observed for systemic and local reactions 30min, 8, 24, 48, 72h after vaccination, their body temperatures and clinical reactions were recorded every other day. Their blood samples were collected 1 and 2 months after vaccination for anti-HAV-IgG and SGPT testing. When followed up as long as 13 and 24 months, anti-HAV-IgG was tested again by EIA competition inhibition assay marked by WHO standard sample (100mIU/ml). The results showed that during the whole period of observation, no medium and severe adverse effects or any clinical reactions were seen, no SGPT abnormality, suggesting that H_2 vaccine is safe. The positive seroconversion rates of this vaccine vaccinated after 2 months, 13-24 months were 99.1%～100% and 97.8%～98.9% respectively. The GMT after 2 months reached 1607mIU/ml and maintained at 448.3mIU/ml after 24 months, which was 4 times higher than that of the same domestic product 2 months after inoculation. The immunogenicity of freeze-dried live attenuated HA vaccine H_2 strain is satisfactory.